BDS-3 B1 signal modulation and multiplexing techniques with receiving performance

Abstract

The navigation signal structure is one of the primary technologies of the satellite navigation system and also a symbol of the BeiDou global navigation satellite system (BDS-3). In this study, the design requirement and challenges of the BDS-3 B1 band signals are first analyzed. After that, the principle and development of an innovative modulation technique, namely Quadrature Multiplexed Binary Offset Carrier (QMBOC) modulation technique, and a generalized multi-frequency multi-component navigation signal constant envelope multiplexing technique, i.e., Constant Envelope Multiplexing via Intermodulation Construction (CEMIC), are introduced in detail. Also, the advanced performance of the new-generation B1 signal is verified through the reception and analysis of the signal transmitted by the BDS-3 satellites. The results from the performance analysis of the signal show that the QMBOC modulation can satisfy the requirements needed for the performance improvement of the next-generation navigation signal, diversified reception modes, as well as the compatibility and interoperability with other navigation systems. Also, the results reveal that the CEMIC multiplexing technique can solve the B1 multiplexing issue caused by the coexistence of new and legacy signals, as well as open and authorized signals. The QMBOC modulation and CEMIC multiplexing technique form the core of the BDS B1 signal scheme and, to a great extent, determine the time-frequency domain characteristics, reception performance, and the transmission efficiency of the signals, which embodies both the innovation of these techniques and their value in engineering application. Presently, these techniques have been applied to all BDS-3 satellites and provide services to the world, which becomes a major hallmark of BDS-3 surpassing the advanced level of the world.